1000m Loop Amplifier

The Opus Single-Channel Class D Induction Loop Amplifier LD3.0 provides assisted listening for large rooms using a single induction loop. Designed for permanent installations, it delivers audio to compatible telecoil-equipped hearing aids in applications such as auditoriums, conference facilities, lecture theatres and places of worship.

Opus specifies indicative coverage of up to 900 m², subject to room geometry, listening height and surrounding metal. The amplifier delivers 10A RMS output current at 1kHz, with a peak current capability of 15A, and supports loop impedances from 0.5 to 3Ω. A SmartLoop design study is recommended to assess coverage and establish the appropriate cable layout before installation.

Three audio inputs provide flexibility when connecting microphones and existing sound equipment. Two inputs are switchable between line and microphone operation, while a priority 100V input supports integration with a suitable public address system. A 12V / 2mA phantom supply is available for compatible microphones.

Compression and automatic gain control help manage variations in source level. Adjustable metal loss correction from 0 to 3dB per octave allows installers to compensate for the effects of nearby metal on loop performance, helping maintain a balanced audio response.

Continuous monitoring checks the amplifier and loop. Front-panel indicators show power, protection, clipping and loop status, while an NO/NC fault relay provides a contact output for external fault monitoring. This allows maintenance teams to check operation locally and receive fault information through a connected monitoring system.

The LD3.0 incorporates a 115/230V AC, 50/60Hz power supply within an enclosure measuring 42 × 200 × 215 mm and weighing 1.48kg. Final commissioning should verify loop performance throughout the intended listening area, taking account of the room’s installation constraints.